In a conventional vehicle steer axle assembly, a steering knuckle assembly may include a body, steering arms, a brake mounting plate, a spindle for a wheel hub, bearings, and a tire assembly (see, for example, U.S. Pat. No. 6,623,019 which is incorporated herein by reference). The steering knuckle is coupled to a steer axle using a separable kingpin and the steering arms are connected to steering components of a vehicle.
Typically, the steering knuckle has a forked yoke that defines first and second knuckle body bosses with aligned bores. The yoke partially surrounds one end of the steer axle which defines an axle boss having an axle bore aligned with the knuckle body bores of the knuckle yoke. The kingpin extends through a first knuckle body bore, through the axle bore, and through the remaining knuckle body bore to rotatably couple the knuckle and the steer axle together.
In these conventional steer axle assemblies, the knuckle pivots about the kingpin on a vertically inclined steering axis. Typically, bushings are disposed (for example, pressed) within the aligned bores of the knuckle body to allow the knuckle to rotate relative to the kingpin.
In addition, some knuckles have upper and lower steering bores wherein the steering arms and tie rod arms are disposed. The steering arms and the tie rod arms are utilized to control the steering of the vehicle. These knuckle steering bores are typically inclined horizontally.
Conventional steer axle assemblies, however, suffer from several disadvantages. Typically, the shapes of the knuckle steering bores are different for each side of the vehicle and the knuckle steering bores are sized uniquely for each steer axle assembly and may be sized uniquely from knuckle top to knuckle bottom, due to, for example, the assembly direction (i.e., forward to rear (rearwardly directed) or rear to forward (forwardly directed)) of entry of the steering/tie rod arm into the knuckle steering bores. As a result, separate knuckles are required for each side of the vehicle, which requires higher design, material, manufacturing, labor, inventory, and operational costs.
U.S. Pat. No. 4,761,019 to Dubensky discloses a steering knuckle fabricated of sheet metal that is usable as a left hand or a right hand steering knuckle by orienting the control arm channels to point in one direction or the other. Dubensky requires three channels that utilize ball joints to mount upper and lower control arms or tie rods and requires the control arm channels to be symmetrical about a horizontal axis so that the steering knuckle may be used on either side.
Today, knuckles need to be robust (e.g., forged steel versus sheet metal) and often require the ability to be mechanically coupled to a tie rod on both sides of a vehicle. In addition, the steering arms are not only connected to a knuckle in a forewardly directed manner but are also connected to the knuckle steering bore in a rearwardly directed manner. This, however, requires the use of different vehicle knuckles for both sides of the vehicle.
Thus, what is sought is to provide a robust vehicle steer axle assembly that does not utilize separate knuckles for each side of a vehicle, for each steer axle, or for the assembly direction of entry of the steering/tie rod arms into the knuckle steering bores. This should at least result in providing vehicle steer axle assemblies with lower material, inventory, design, manufacturing, labor, and operational costs.